Can anyone help me out there? I'm currently trying to design an irrigation system and can't manage to find any design information on the Blue water supply pipes. I am looking for tables covering pressure (head)/friction factors/pipe size/ flow rates etc. If someone could point me in the right direction it would be greatly appreciated. Thanks

What exactly are you trying to irrigate is  it for a garden or industrial scale?

http://www.engineeringtoolbox.com/pvc-pipes-friction-loss-d_802.html

Edited September 5, 20169 yr by Anythingleft?
Addition

be warned Thai blue  pipes are "odd " sizes , for example 1 inch 25mm pipe has an internal diameter  of actually 28mm which is good in some ways, the pressure ratings are on the side of the pipe written in blue 5 bar.8.5  bar, 13  bar and upwards

You can use this to calculate friction loss etc http://www.freecalc.com/fricfram.htm

For irrigation you might want to consider SuperProducts or Netafim. All manner of videos of Netafim in English as well as Thai. The Buriram Province Netafim dealer sent a bi-lingual Netafim employee technical  rep to my wife's village garden plot on Highway 2229 to do a free design plan. The OP might visit the Netafim dealer is in his province.  I've noted that 5 bar or 8.5 bar or 13.5 bar Blue PVC pipes of different brands do not always measure the same. HDPE and PE are both black pipe used in some irrigation projects. But the sizes are not the same. Certainly items to buy in person and to double check your valves, drip connectors all will connect properly.  Quite a selection of information on the Netafim web sites.

http://www.netafim.com/